The pair called for the extension of sugar taxes, which were brought in for non-dairy drinks last month, along with a clampdown on marketing of unhealthy foods, and a ban on TV junk food advertising before 9pm.

Later this year the Government is expected to announce new measures to tackle childhood obesity.

Its first strategy, published in August 2016, set out plans for a sugar tax on soft drinks, but did not clamp down on marketing or advertising of unhealthy foods.

The plans met criticism from some food campaigners, with Theresa May’s former chief of staff boasting that they had “saved Tony the Tiger” - the mascot for Kellogg’s Frosties.

Mr Oliver urged ministers to go further this time, as he described the sugar tax as a “fantastic policy” suggesting it should be extended to cover sugary dairy drinks.

Critics have suggested such taxes unfairly hit the poor. But the chef and food campaigner said the use of the funds - to pay for sports facilities and healthy eating clubs - meant it benefited deprived areas.

“This a tax for good; this is a tax for love; this is designed to protect and give to the most disadvantaged communities,” he told MPs.

Both chefs said there was a case for extending the taxes to other drinks.

"I definitely don't think we should overuse taxing, but I think there is some logic to opening it out to milk products, which are jam-packed with additives and sugar and they're currently outside of that taxing,” Mr Oliver said.

The chef held up a bottle of the strawberry-flavoured Yazoo milk drink, telling MPs that it contained 33 grams or nine teaspoons of sugar, while Mr Fearnley-Whittingstall held a bottle of Mars milk drink, which he told the committee contained 10 teaspoons of sugar.

He called for a halt on “the use of cartoons and aspirational superheroes to peddle rubbish” - highlighting previous efforts to demand curbs on marketing of sugary foods.

Mr Oliver told MPs: “I love a bit of Tony the Tiger. We are both getting on a bit. I think he feels pretty sorry for peddling very unhealthy breakfasts for a long time. I don’t want to make him redundant I want to promote him.

“If he wants to promote porridge oats and Weetabix and Shreddies and anything that makes you glow when you walk to school then I’m all in,” he said.

Mr Fearnley-Whittingstall, currently presenting Britain’s Fat Fight on BBC1, added: “It costs more to treat type two diabetes and obesity related disease than it does to run the police service, the fire service and the judiciary in this country.”

The session came amid a growing backlash to Mr Oliver’s campaign, #AdEnough, which calls on the government to ban fast food adverts before the watershed, with commentators highlighting high levels of sugar and fat on his restaurant menus.